کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1232568 | 968793 | 2010 | 7 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Recognition of DNA based on changes in the fluorescence intensity of CdSe/CD QDs–phenanthroline systems Recognition of DNA based on changes in the fluorescence intensity of CdSe/CD QDs–phenanthroline systems](/preview/png/1232568.png)
The CdSe quantum dots (QDs) modified by mercapto-β-cyclodextrin (CD) were synthesized and characterized by transmission electron microscopy, powder X-ray diffraction, excitation and emission spectra, and fluorescence lifetime. When λex = 370 nm, the fluorescence peak of CdSe/CD QDs is at 525 nm. Phenanthroline (Phen) is able to quench their fluorescence, which can be recovered by the addition of DNA. The quenching and restoration of fluorescence intensity were found to be linearly proportional to the amount of Phen and DNA, respectively. The variation of the fluorescence intensity of the CdSe/CD QDs–Phen system was studied, and it was demonstrated to result from a static mechanism due to the formation of a Phen inclusion complex with the CdSe QDs modified by mercapto-β-cyclodextrin. The fluorescence recovery was due to the binding of DNA with Phen in the inclusion complex, leading to the freeing of the CdSe/CD QDs. The binding constants and sizes of the binding sites of the Phen–DNA interaction were calculated to be 1.33 × 107 mol−1 L and 10.79 bp.
Journal: Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy - Volume 75, Issue 5, May 2010, Pages 1617–1623